Shellfish poisoning restricts harvesting, causes bay closure
Diarrhetic shellfish poisoning biotoxin levels have recently been detected in Bellingham Bay and have gone over the limit for safe harvesting, said Tom Kunesh, environmental health supervisor for the Whatcom County Health Department.
Currently, the Whatcom County Health Department is concerned with the diarrhetic shellfish poisoning that been detected in shellfish in the surrounding Bellingham waters where recreational harvesting takes place, Kunesh said.
Because of the high levels of toxins, the Washington State Department of Health has closed Bellingham Bay, Portage Bay and all waters south to Skagit County, which included all of Larrabee State Park, for recreational shellfish harvesting, said Kunesh.
“Long term health effects [include] proneness to cancer in the future with folks that have been intoxicated with diarrhetic shellfish poisoning,” Kunesh said. “The main immediate concern is that is causes nausea, diarrhea and upset stomach. It can be severe and generally not life threatening.”
The earliest expected date waters will reopen is Friday, July 24. Kunesh said the Department of Health’s sampling protocol requires at least two consecutive weeks of samples that are below the closure limit before they reopen an area to recreational harvest.
Marine biotoxins refer to “poisons that are produced by certain kinds of microscopic algae that are naturally present in marine waters, normally in amounts too small to be harmful,” according to the Washington State Department of Health’s website.
“Although toxin levels have increased above a limit that is considered safe, they are not yet at levels where we worry about people getting extremely ill,” said Kunesh. “They are near the closure limit, not fanatically above the closure limit.”
“There is no way to predict whether the levels will increase or decrease,” Kunesh said. “If we get a good shot of rain this weekend then we might see levels increase next week.”
The Whatcom County Health Department partners with the Washington State Department of Health to monitor marine waters for biotoxins that can affect the safety of molluscan shellfish, Kunesh said.
Kunesh said inland Puget Sound and coastal waters are routinely checked for three biotoxins: paralytic shellfish poisoning – also known as red tide – , amnesic shellfish poisoning and diarrhetic shellfish poisoning, which are all found in plankton.
Toni Knudson, manager of Buck Bay Shellfish Farm on Orcas Island, said there is an increase in sales for commercial suppliers due to the recreational shellfishing closures because it’s the only way for residents to get safe, toxic-free shellfish.
“They only places [residents] can get fresh shellfish is from us or another shellfish supplier,” Knudson said.
Diarrhetic shellfish poisoning effects recreational harvesting far worse than its does commercial, Knudson said.
“The way Washington state works is if they have a sight that is south of the San Juan Islands than they will shut the entire San Juan Islands down for harvesting,” Knudson said. “For commercial they will only shut us down if it’s in our area and if the shellfish has tested positive for it specifically.”
Commercial harvesters, including restaurants, are required to send their products to a lab before harvest for sale to test that their biotoxin levels are at a safe limit within the shellfish, Kunesh said.
Cooking shellfish does not destroy biotoxins, Kunesh said.
“If you harvest during a biotoxin closure that doesn’t work,” Kunesh said. “These are chemical toxins that are not denatured by cooking.”
Residents interested in recreationally harvested shellfish are advised to check the biotoxin hotline or the Department of Health’s website for biotoxin levels, Kunesh said. Recreational harvesters should also check the Washington State Department of Fish and Wildlife website to make sure fishing license requirements are met and beaches are open on a resources protection standpoint, Kunesh said.
“You don’t want to be out there because public health said it was okay, but fish and wildlife says we are going to write you a ticket, or vice versa,” said Kunesh.
Bill Dewey, director of public affairs for Taylor Shellfish Farms along Chuckanut Drive, said that a lot of times when toxins are detected, the Department of Health will have a closure.
“In an abundance of caution when [the Department of Health] has toxins in an area they will close broad areas for recreational harvest because they don’t have the resources to monitor those beaches as closely,” Dewey said.
Commercial farms aren’t closed because under the national shellfish sanitation program and certifications. The State Department of Health monitor the toxin levels on the farms a lot more closely than they are able to on recreation beaches, Dewey said.
“For shellfish farms, part of our annual fee that we pay to the Department of Health is to cover frequent testing for animals off our farms to ensure that they are safe,” Dewey said.
Kunesh advises residents who become sick from biotoxin-type illnesses should seek medical attention.
“Contact your medical provider immediately,” Kunesh said. “In severe cases there may be supportive care that is required to get someone back to good health.”